UT/UT_Functor.C

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 * 
 * Produced by:
 *      Luke Moore
 *      Side Effects Software Inc
 *      477 Richmond Street West
 *      Toronto, Ontario
 *      Canada   M5V 3E7
 *      416-504-9876
 *
 * NAME:        UT_Functor.C
 *
 *      This file contains template specializations for UT_Functor.  They
 *      cannot go into UT_Functor.h because compilers that don't use the
 *      Borland template compilation model will fail because of multiply
 *      defined symbols.
 */

#ifndef __UT_Functor_C__
#define __UT_Functor_C__

#include "UT_Functor.h"

// It's okay for a functor with a void return type to not do anything if
// it was never initialized.  This can happen if you just declare a
// functor with the default constructor but never initialize it.
template <>
inline void
UT_Functor<void>::operator()() const
{
    if (myFunctorImpl.myFunctorImpl)
        (*myFunctorImpl.myFunctorImpl)();
}

// ---------------------------------------------------------------------------

// Irix doesn't let you use "return <expression>" when <expression>'s type is
// void.  We can't partially specialize member functions, so instead we have
// to partially specialize the classes to when a void return type is used.
template <typename PointerToObj, typename PointerToMemFn>
class UT_MemFunHandler<UT_Functor<void>, PointerToObj, PointerToMemFn>
    : public UT_FunctorImpl<void>
{
public:
    typedef void ReturnType;

    UT_MemFunHandler(const PointerToObj &pointer_to_obj,
                     const PointerToMemFn pointer_to_mem_fn)
        : myPointerToObj(pointer_to_obj), myPointerToMemFn(pointer_to_mem_fn)
    {}

    virtual UT_FunctorImpl<void> *clone() const
    {  return new UT_MemFunHandler<UT_Functor<void>, PointerToObj,
                                   PointerToMemFn>(*this); }

    // There is no "return" here, because Irix doesn't support it.
    virtual void operator()() const
    { ((*myPointerToObj).*myPointerToMemFn)(); }

private:
    PointerToObj         myPointerToObj;
    PointerToMemFn       myPointerToMemFn;
};

// ---------------------------------------------------------------------------

template <typename P1, typename PointerToObj, typename PointerToMemFn>
class UT_MemFunHandler1<UT_Functor1<void, P1>, PointerToObj, PointerToMemFn>
    : public UT_FunctorImpl1<void, P1>
{
public:
    typedef void ReturnType;
    typedef P1 Parm1Type;

    UT_MemFunHandler1(const PointerToObj &pointer_to_obj,
                      const PointerToMemFn pointer_to_mem_fn)
        : myPointerToObj(pointer_to_obj), myPointerToMemFn(pointer_to_mem_fn)
    {}

    virtual UT_FunctorImpl1<void, P1> *clone() const
    {  return new UT_MemFunHandler1<UT_Functor1<void, P1>, PointerToObj,
                                    PointerToMemFn>(*this); }

    // There is no "return" here, because Irix doesn't support it.
    virtual void operator()(Parm1Type parm1) const
    { ((*myPointerToObj).*myPointerToMemFn)(parm1); }

private:
    PointerToObj         myPointerToObj;
    PointerToMemFn       myPointerToMemFn;
};

// ---------------------------------------------------------------------------

template <typename P1, typename P2,
          typename PointerToObj, typename PointerToMemFn>
class UT_MemFunHandler2<UT_Functor2<void, P1, P2>, PointerToObj, PointerToMemFn>
    : public UT_FunctorImpl2<void, P1, P2>
{
public:
    typedef void ReturnType;
    typedef P1 Parm1Type;
    typedef P2 Parm2Type;

    UT_MemFunHandler2(const PointerToObj &pointer_to_obj,
                      const PointerToMemFn pointer_to_mem_fn)
        : myPointerToObj(pointer_to_obj), myPointerToMemFn(pointer_to_mem_fn)
    {}

    virtual UT_FunctorImpl2<void, Parm1Type, Parm2Type> *clone() const
    {  return new UT_MemFunHandler2<UT_Functor2<void, P1, P2>, PointerToObj,
                                    PointerToMemFn>(*this); }

    // There is no "return" here, because Irix doesn't support it.
    virtual void operator()(Parm1Type parm1, Parm2Type parm2) const
    { ((*myPointerToObj).*myPointerToMemFn)(parm1, parm2); }

private:
    PointerToObj         myPointerToObj;
    PointerToMemFn       myPointerToMemFn;
};

template <typename P1>
class UT_Functor1<void, P1>
{
public:
    typedef void ReturnType;
    typedef P1 Parm1Type;

    UT_Functor1() {}

    explicit UT_Functor1(
                UT_FunctorImpl1<void, Parm1Type> *functor_implementation)
    : myFunctorImpl(functor_implementation)
    {}

    template <typename FunctorType>
    UT_Functor1(FunctorType functor)
    : myFunctorImpl(new UT_FunctorHandler1<UT_Functor1, FunctorType>(functor))
    {}

    template <typename PointerToObj, typename PointerToMemFn>
    UT_Functor1(const PointerToObj &pointer, PointerToMemFn method)
    : myFunctorImpl(new UT_MemFunHandler1<UT_Functor1, PointerToObj,
                                          PointerToMemFn>(pointer, method))
    {}

    ~UT_Functor1()
    {
        delete myFunctorImpl.myFunctorImpl;
        myFunctorImpl.myFunctorImpl = 0;
    }

    UT_Functor1 &operator=(const UT_Functor1 &functor)
    {
        if (&functor != this)
        {
            delete myFunctorImpl.myFunctorImpl;
            myFunctorImpl.myFunctorImpl = functor.myFunctorImpl.myFunctorImpl
                        ? functor.myFunctorImpl.myFunctorImpl->clone() : 0;
        }
        return *this;
    }

    // There is no "return" here, because Irix doesn't support it.
    void operator()(Parm1Type parm1) const
    {
        UT_ASSERT(myFunctorImpl.myFunctorImpl);
        (*myFunctorImpl.myFunctorImpl)(parm1);
    }

    bool isSet() const
    { return myFunctorImpl.myFunctorImpl != 0; }

private:
    class Helper
    {
    public:
        Helper() : myFunctorImpl(0) {}

        // Clone the other functor's implementation in the copy constructor.
        Helper(const Helper &helper)
        { myFunctorImpl = helper.myFunctorImpl
                        ? helper.myFunctorImpl->clone() : 0; }

        explicit Helper(
                UT_FunctorImpl1<void, Parm1Type> *functor_implementation)
            : myFunctorImpl(functor_implementation) {}

        template<typename U>
        explicit Helper(U *ptr) : myFunctorImpl(ptr) {}

        UT_FunctorImpl1<void, Parm1Type> *myFunctorImpl;
    };

    Helper myFunctorImpl;
};

// ---------------------------------------------------------------------------

template <typename P1, typename P2>
class UT_Functor2<void, P1, P2>
{
public:
    typedef void ReturnType;
    typedef P1 Parm1Type;
    typedef P2 Parm2Type;

    UT_Functor2() {}

    explicit UT_Functor2(
            UT_FunctorImpl2<void, Parm1Type, Parm2Type> *functor_impl)
    : myFunctorImpl(functor_impl)
    {}

    template <typename FunctorType>
    UT_Functor2(FunctorType functor)
    : myFunctorImpl(new UT_FunctorHandler2<UT_Functor2, FunctorType>(functor))
    {}

    template <typename PointerToObj, typename PointerToMemFn>
    UT_Functor2(const PointerToObj &pointer, PointerToMemFn method)
    : myFunctorImpl(new UT_MemFunHandler2<UT_Functor2, PointerToObj,
                                          PointerToMemFn>(pointer, method))
    {}

    ~UT_Functor2()
    {
        delete myFunctorImpl.myFunctorImpl;
        myFunctorImpl.myFunctorImpl = 0;
    }

    UT_Functor2 &operator=(const UT_Functor2 &functor)
    {
        if (&functor != this)
        {
            delete myFunctorImpl.myFunctorImpl;
            myFunctorImpl.myFunctorImpl = functor.myFunctorImpl.myFunctorImpl
                        ? functor.myFunctorImpl.myFunctorImpl->clone() : 0;
        }
        return *this;
    }

    // There is no "return" here, because Irix doesn't support it.
    void operator()(Parm1Type parm1, Parm2Type parm2) const
    {
        UT_ASSERT(myFunctorImpl.myFunctorImpl);
        (*myFunctorImpl.myFunctorImpl)(parm1, parm2);
    }

    bool isSet() const
    { return myFunctorImpl.myFunctorImpl != 0; }

private:
    class Helper
    {
    public:
        Helper() : myFunctorImpl(0) {}

        // Clone the other functor's implementation in the copy constructor.
        Helper(const Helper &helper)
        { myFunctorImpl = helper.myFunctorImpl
                        ? helper.myFunctorImpl->clone() : 0; }

        explicit Helper(
                UT_FunctorImpl2<void, Parm1Type, Parm2Type> *functor_impl)
            : myFunctorImpl(functor_impl) {}

        template<typename U>
        explicit Helper(U *ptr) : myFunctorImpl(ptr) {}

        UT_FunctorImpl2<void, Parm1Type, Parm2Type> *myFunctorImpl;
    };

    Helper myFunctorImpl;
};

#endif

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